Upper Rio Grande Basin Focus Area Study

Methods

Water Use

Available water-use data from the USGS water-use compilations for Colorado, New Mexico, and Texas (1985-2015), other completed studies, and new approaches will be assessed to evaluate water use and withdrawal trends in the URGB.

Water-use information is independently valuable; however, spatial integration of water-use data with natural-flows data will identify areas of water-supply stress, and help to inform water and ecosystem management efforts. Sources from which water is withdrawn (both surface water and groundwater), the demand that the water is used to satisfy, the transport of the water to the location of demand (including transmission losses), the amount of water that is “consumed” in satisfying the demand, and the volume and location of water returned to the environment, either as return flows to surface water or recharge to groundwater systems, will be determined as part of the URGB FAS. That information will then be compiled, integrated, and spatially distributed.

Study Component Lead

Tammy Ivahnenko

USGS Colorado Water Science Center

Sources, Locations, and Use of Withdrawals

Improved understanding and estimates of water-use will be one of the most essential outcomes of the URGB FAS. By focusing effort on water use, the USGS will be better able to characterize how humans move, utilize, consume, and dispose of the water they withdraw, divert, or impound and to integrate that information with an understanding of natural flows in the environment. The approach to complete this study component is:

Update Regional Databases
  1. Coordinate with the USGS 2015 water-use compilation, which compiles county-based annual withdrawals by source for major and minor categories of use. Re-aggregate these data at the HUC-8 scale.
  2. Complete the Site-Specific Water Use Database System (SWUDS).
  3. Incorporate site-specific return flows (discharge) from municipal and industrial facilities to surface-water bodies.
Define withdrawals by major water-use categories
  1. All new and existing water-use information will be compiled into a comprehensive and consistent format in SWUDS and AWUDS.
  2. Water-use, by major category (for example, agricultural, municipal, and thermoelectric) and source (for example, surface-water feature, aquifer) will be determined.
Spatial Distribution of Withdrawals
  1. Spatially distribute withdrawals at the HUC-8 scale for all categories for the 2015 compilation. In addition, water use for all categories in the years 2000, 2005 and 2010 will be re-aggregated to the HUC-8 to be used in trend analysis for the years 1985 to 2015. If data are available, 2015 water use data may be distributed at the HUC-12 scale for all water use categories.

Consumptive Use

Consumptive use (CU) of water is an important factor for determining water availability. Additionally, many regional stakeholders and water-supply managers have indicated CU as a primary focus of their management strategies, yet there is a lack of available data in this area. The URGB FAS will make an investment in expanding the knowledge of consumptive uses for the irrigation, thermoelectric, and provided there are enough data, domestic sectors. The approach to complete this study component is:

  • Supply basin-wide information on consumptive uses by thermoelectric facilities for water withdrawal and return flows by contacting state agencies or the facilities directly for withdrawal data.
Evapotranspiration Estimates
  • Produce monthly and seasonal ET grids at the Landsat scale using the Simplified Surface Energy Balance (SSEBop) ET model for the URGB for 2015.
Field Verification
  • Verify irrigated acreage and riparian habitat in select areas to improve estimates of CU for irrigation.
Thermoelectric Facilities
  • Supply basin-wide information on consumptive uses by thermoelectric facilities for water withdrawal and return flows by contacting state agencies or the facilities directly for withdrawal data.

Domestic Water Use

Approximately 12 percent of the population in the URGB is estimated to have self-supplied household water. Domestic water use, as estimated by the New Mexico Office of the State Engineer (NMOSE), is based upon an area-wide average calculated by Brown and Caldwell and adjusted in selected counties where landscape irrigation and evaporative cooling are used. Current indoor conservation measures are not included in the domestic water-use estimates, and information on outdoor water uses is sparse.

As part of this project, updated estimates of indoor domestic water use will be developed using selected geospatial datasets including domestic well locations and water-use data from metered domestic wells. Outdoor domestic use for landscape and garden irrigation will be assessed in selected subbasins using municipal park irrigation data applied to average lot sizes in urban and suburban areas. Domestic water use will be compared to other major water-use sectors to determine the possible effects of domestic withdrawals on groundwater and surface-water reserves. This study component will provide better and more current estimate coefficients incorporating household conservation methods and appliances for the NMOSE, as well as transferable coefficients for other arid and semi-arid Western States. The approach to complete this study component is:

Indoor Water Use
  1. Coordinate with the cities of Albuquerque, New Mexico and El Paso, Texas water utilities to determine deliveries for domestic water use. Include smaller water utilities to determine deliveries for domestic water use.
  2. Coordinate with other scientists on their work to determine water conservation methods in cities in the Southwestern United States.
  3. Coordinate with the cities of Albuquerque, New Mexico and El Paso, Texas water utilities to determine number of households that have applied for, and installed water-saving appliances and fixtures through the indoor water-use rebate programs.
  4. Identify self-supplied, owner-occupied domestic households with varying median values that are metered.
  5. Acquire monthly residential billing information [amount of water and general address zip code)] from the cities of Alamosa, Colorado; Albuquerque, New Mexico; and El Paso, Texas water utilities, as well as other smaller water utilities.
  6. Use websites such as http://www.nmprc.state.nm.us/consumer-relations/company-directory/water/index.html for determining water deliveries to connections by public supply purveyors in New Mexico.
  7. Use the Colorado Decision Support System (http://cdss.state.co.us/onlineTools/Pages/StructuresDiversions.aspx) to retrieve water withdrawal data for domestic wells.
  8. Use the website http://www.epwu.org/water/water_stats.html to determine water sold to residential customers in the City of El Paso, Texas.
  9. Use census block data to determine number of people per household and apportion population to land use data using the USGS Dasymetric Mapping Tool.
  10. Use an automated process to randomly select houses in subdivisions where water-billing information was received and determine the number of bathrooms, square footage.
  11. Use the water-saving appliance and water fixture rebate program data to estimate number of households that are using the water saving devices, and compare to households that do not have water saving appliances and fixtures.
  12. Estimate the number, use, and age of swamp coolers in the basin—this could require looking at self-supplied domestic areas in ‘Google Earth’ and some driving past and through these areas to verify use of swamp coolers.
  13. Obtain self-supplied domestic water meter data from NMOSE and determine number of people in the household, use of water saving appliances and fixtures, number of baths in the house, and extent of outdoor irrigation and system type.
  14. Use established methods to confirm or correct domestic self-supplied estimates.
Outdoor Water Use
  1. Use the SSEBop ET data for estimating urban/suburban outdoor water use, however knowing that the water that was used for irrigation is public supply.
  2. Using Landsat SSEBop, estimate ET for landscaped/xeriscaped areas such as botanical parks, golf courses, or other non-turf parks.
  3. Acquire local Homeowner Association rules and covenants on amount of turf allowed in subdivisions.
  4. Acquire water utility xeriscape rebate data, for number of homes that have removed turf and replaced with water-saving plants and replaced or installed micro-or drip irrigation systems.